Virtual reality (VR) is a computer simulation that creates or replicates an environment, imagined or real, and simulates a user's physical presence in that environment to allow for user interaction. VR systems, through various visual, audio, and tactile sensors, may artificially create an almost total sensory immersion experience for a user.
Augmented reality (AR) is a live direct or indirect view of a physical, real-world environment whose elements are augmented or supplemented by computer-generated sensory input such as sound, video, graphics, or other data. Using AR systems, the information about the surrounding real world of the user becomes interactive and digitally manipulable. Information about the environment and its objects is overlaid on the real world. The overlaid information may be a virtual object or real object overlaid on the real world.
VR and AR systems are gaining in popularity due to faster, more powerful computers, improved high resolution displays, and new content being written for these systems. The VR and AR generated environments may become so real and the user immersion so intense, that even the simulated environments may have physical and/or emotional consequences for the user.